Weathering erosion and deposition are essential processes that contribute to building mountains and shaping our landscapes. Evidence of this process is visible everywhere: cracks in sidewalks, wedges formed from frozen water forming wedges in rocks, black sand beaches.
Studying how rocks are collected and deposited can provide us with valuable insight into these processes.
Weathering
Weathering, or the breaking down of rock and soil, occurs near the surface of Earth and can be caused by various causes including heating and cooling cycles, frost or crystal wedging and chemical weathering (adding oxygen to minerals such as iron in rocks or by acid rain) as well as plants or microbes.
Biological weathering refers to the process by which plants, animals and microbes break down rocks and minerals into smaller components. This leads to erosion. Mechanical or physical weathering involves breaking down rock and soil using physical means without altering their chemical makeup; examples of such weathering include growing roots exerting pressure on rocks or expanding and contracting during changing temperatures which weaken rocks over time.
Erosion occurs when rock and soil particles are transported away from their original locations by wind, water, ice, plants or gravity and deposited somewhere else, often creating new landforms like mountains, beaches or riverbeds in their path.
Erosion
Erosion is the natural process by which rocks, soil and sand are worn away by liquid water, wind, gravity or glaciers (a form of glaciers).
Physical erosion refers to the dissolution of rocks into smaller particles without altering their chemical makeup, leading to things like shoes scuffing on pavement or cracks in sidewalks and chipped windshield glass; physical erosion also acts as the force behind landslides and similar mass-wasting processes.
Chemical weathering alters the chemical makeup of rocks, leading to changes in their makeup that lead to patterns etched into rocks or formation of pebbles along river beds. Meanwhile, biological erosion uses plants’ action against sediments in order to halt or slow erosion by anchoring roots to sediments that otherwise would be carried away by wind, rain or ice.
Deposition
Weathering breaks apart tiny pieces of earth into smaller ones that can then be moved by erosion, often with drastic results. Erosion may move nearby – such as when rocks collide and smash one into another – or much further away; such as when sand washes up along beaches.
Deposition refers to the process of depositing or adding sediments onto landforms through various means such as wind, ice, water and gravity. As these particles travel back towards their source from erosion sites they deposit new layers of soil forming layers upon layers that ultimately become soil layers.
Physical Erosion
When rocks change shape without changing their basic chemical composition, this is known as physical erosion. Common examples include landslides and crumbling mountains. Plant growth may also contribute to this form of physical erosion by breaking apart rocks as it advances.
Landforms
Landforms are distinct features on Earth’s surface that arise through weathering, erosion and deposition processes to form mountains, valleys, plains or plateaus.
Erosion wears down landscapes with water, wind, ice, and gravity as its agents of destruction. Once this material has been exposed to these forces, it’s carried off or deposited elsewhere by them – such as sediment on beaches or even creating deltas in rivers.
Landforms are subject to various forces that shape them into unique forms. Aeolian forces create sand dunes while volcanic eruptions wear down volcanic necks into mesas, with plains being raised areas bordered on at least one side by land and water that are bordered on both sides by rivers or bodies of water, or formed through erosion and deposits of lava – as well as being formed from erosion and depositions of lava itself. Other features in landscape include cliffs, canyons and volcanoes.